Early high avidity specific IgG production in experimental hamster visceral leishmaniasis

Autor(es)

de Carvalho, Camila Aparecida ^{[1, 2]} ; Ferrao, Thiago Fidelis ^[1] ; Cavalcante, Fernanda Siqueira ^[1] ; Novais de Freitas, Flavia Regina ^[1] ; Meireles, Luciana Regina ^[1] ; de Andrade Junior, Heitor Franco ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Med Trop, Fac Med, Sao Paulo - Brazil

^[2] Inst Med Trop Sao Paulo, Protozool Lab, Ave Doutor Eneas Carvalho Aguiar 470, BR-05403000 Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Parasitology Research; v. 119, n. 11 AUG 2020.
• Citações Web of Science: 0

Resumo

Visceral leishmaniasis (VL) byLeishmania (Leishmania) infantumis epidemic in Brazil. Hypergammaglobulinemia appears early in patients with VL and is ineffective. Usually, high-affinity IgG B cells are selected during most infections, a critical step for an effective humoral response. The avidity of IgG antibodies in VL is unexplored due to the absence of temporal parameters in most patients, associated to low clinical significance. Experimental infection models overcome this fact, allowing the monitoring of the disease temporal evolution. In this study, the avidity of IgG antibodies was evaluated in experimental models, in infection in hamsters, and in immunization in rabbits. Specific IgG antibodies were detected by ELISA, using chaotropic solution to determine avidity, as reported for viral infections. The levels of IgG antibodies correlated with the progression of experimental infection in hamsters or antigenic stimulation in immunized rabbits. However, IgG avidity was high early in infected animals, even in early periods (> 80%), while in immunized rabbits, they had early antibodies of low avidity with progressive maturation, similar as other infections. These data suggest that the affinity maturation of the avidity of anti-LeishmaniaIgG antibodies promoted at an early stage, influencing the appropriate interaction between antigens and affecting the disease progression. This fact could be associated to monovalent immune complexes, as reported in human and experimental VL. This scenario may be related to an independent process of immune cell activation by the parasite but absent in antigen preparation used as immunogens. (AU)

• Processo FAPESP: 17/26558-9 - Haptenos na leishmaniose visceral. Desenvolvimento de ensaios de fase sólida para diagnóstico e sua imunologia em modelos experimentais.
• Beneficiário: Heitor Franco de Andrade Junior
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 17/14675-0 - Resposta imune humoral a haptenos de L. (L.) infantum chagasi por detecção de anticorpos específicos e naturais na leishmaniose visceral experimental e natural
• Beneficiário: Camila Aparecida de Carvalho
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado